The present invention refers to an improved lance driving mechanism for shuttleless looms which is superior to any presently known as far as proper mechanism applications and possible use to operatively convert a shuttle loom into a shuttleless one are concerned.
U.S. application Ser. No. 583,973 refers to a mechanism comprising fundamentally lances and associated first members thereof arranged on a sley including a first rotation sector, which sector is linked to a connection rod with its other end eccentrically pinned to a plate or wheel which rotates two turns for each complete stroke of the sley. As a result there are obtained lance neutral, acceleration and deceleration points in accordance with the most suitable points or time for the purposes.
Such a mechanism having the present invention applied thereto is thus improved, firstly because of the inclusion of a sector fitted to a support engaged shaft and close to the support bottom whereto another self-rotation shaft is located, matching the sley shaft and with an eccentric unit to adjust the height of the support. This support carries a wing fitted to the sley and incorporates the band driving arrangement. Also significant is the fact that the plate rotates two turns for each sley stroke, carries eccentricity adjustment means and can be driven from the loom crankshaft or from the loom camshaft.
Also this design enables conversion of a shuttle loom into a shuttleless loom. Consequently, it envisages the replacement of the shuttle discharge, locking and control means of a conventional loom, such as: the ejection mechanism comprising cams, picking shaft, pickerstick knuckle unit, pickerstick, pickerstick sweeper and pickerstick shields; the shuttle braking mechanism such as the mechanical or oil-pneumatic dampers and locking strips; guiding mechanisms such as guides and plates; and the shuttle flight retaining mechanism such as flexible stops, movable reed systems or electronic systems. This will enable the provision of a new driving unit comprising a band discharge and guiding sub-unit and a sub-unit to correct the band motions while travelling outside the warp.
Other mechanisms such as the shuttle or "shield" position detector, mechanical push-buttons of the weft reserve in the pirn located within the shuttle and those provided for the replacement of an empty pirn by another full one may thus be eliminated or dispensed with in the new system.